Triple valve for compressed air brakes



Nov. 28, 1933. F. KASANTZEFF TRIPLE VALVE FOR COMPRESSED AIR BRAKES Filed April 23, 1930 In venfor:

Patented Nov. 28, 1933 a,

1 1,936,966 TRIPLE vALvE roa COMPRESSED AIR BRAKES Florentin Kasantzefl', Berlin, Germany Application April 23, 1930, Serial No. 446,732, and

in Germany October 15, 1929 4 Claims.

This invention relates to triple valves for single chamber automatic compressed air brakes particularly of the direct-acting type, and the essential feature consists mainly in providing the 5 control valve with devices acting in such manner that independently of any overcharge of the auxiliary reservoir and independently of a too great depression in the train pipe a desired maximum degree of braking is never transgressed.

Further valuable developments of the invention will appear from the following detailed description.

The accompanying drawing illustrates the improved triple valve in longitudinal section with simplified representation of the outer parts belonging thereto.

Referring to the drawing, to the triple valve proper are connected a brake cylinder A, an auxiliary reservoir B, a supplemental reservoir C, and the train pipe D. The triple valve contains the following chambers, namely, standard pressure chamber E connected to the supplemental reservoir C, train pipe chamber F, atmospheric chamber G, first brake cylinder chamber H, second brake cylinder chamber I, and valve chamber K connected to the auxiliary reservoir B. The main controlling members are diaphragms L, M, N and between the first two diaphragms L and M a shut-off partition 0 is inserted.

The train pipe chamber F is connected to the train pipe D by two paths, namely, by one path across a dust chamber 1 and an alternately restricted and enlarged passage 2 composed of a series of perforated plates each having a small or a large passage respectively and a channel 6,

and by a second path across the dust chamber 1 and channels 3, 4, 5 and 6, which second path is adapted to be closed, when a certain small pressure is obtained in the brake cylinder, by a piston valve 20 governed at its upper side by the brake cylinder pressure existing in chamber 9 and at its lower side by the atmospheric pressure and below its rod by the train pipe pressure respectively as described later.

'Ihe pressure produced in the train pipe chamber F acts on the right side of the diaphragm L, the left side of which'is acted upon by the standard pressure existing in the chamber E and the supplemental reservoir Crespectively.

The standard pressure chamber E and the supplemental'reservoir C connected to it are connected through the channel 8 with a small opening '7 to the space 4 governed by the above named "controlling piston valve 20, so that with the release of the brakes they are connected to the train pipe D, but during the braking they are shut' all from it, as later described, and therewith always retain the release pressure of the train pipe. In the standard pressure chamber E a spring casing 23 closed against the chamber 5 E and open to the chamber F is tightly fastened centrally to fit diaphragm L, and in the same is located a previously tensioned regulating spring 22 which by its end directed towards the train pipe chamber F presses upon a freely supported 5 spring plate 24 held in its normal position by an abutment fixed on the diaphragm L.

Opposite to this spring plate, so as to act together with it and with the diaphragm L respectively, terminates a piston rod 21 which connects together the two brake cylinder chamber diaphragms M and N and passes tightly packed through the intermediate partition 0. The piston rod 21 contains a passage 19 forming an outlet for the brake cylinder and leading from the brake cylinder chamber J to the atmospheric chamber G which passage is controlled by a double valve 18 acting as a charging and blow off member controlling the inlet and outlet of the brake cylinder.

The atmospheric chamber G stands in connection with an atmospheric outlet 26 through a channel 25.

The first brake cylinder chamber H may be in connection, through a channel 14, with an axial groove 15 of a cock 16 leading to the atmosphere, which also contains an angle passage 1'7 and serves for the adjustment for loaded and unloaded cars. With the cook 16 in the position shown, which is that for loaded cars, the first brake cylinder chamber H is connected to the atmosphere by passages 14, 15, so that the larger diaphragm M being acted upon at both sides by atmospheric pressure is ineffective and the smaller diaphragm N being loaded on one side by the brake cylinder pressure and at the other side by atmospheric pressure, in connection with the diaphragm L being loaded by the standard pressure and the train pipe pressure respectively, is elfective for operating the double valve 18. For unloaded cars the cook 16 is turned to connect the chambers H and I, whereby the diaphragm N being acted upon at both sides by brake cylinder pressure is made ineffective and the larger diaphragm M, in connection with the diaphragm L,is effective to determine the brake cylinder pressure. p

The valve chamber K is connected to the auxiliary reservoir B.through a throttled passage and is in connection, through the double valve 18, with the second brake cylinder chamber 1 so as to form an air inlet for the brake cylinder. Further, the chamber K is connected through a check valve 12 and channels 3, 4 with the train pipe D. The chamber K also is in connection through a narrowpassage 9, adapted to be closed by the rod of the piston valve 20, and a channel 10 with the channelpiece 4 connected to the train pipe D.

In a cylindrical portion of the second brake cylinder chamber I the above named controlling piston valve 20 is slidably arranged so that the upper side of the piston is acted upon by the brake cylinder pressure, while the space on the lower side of the piston is connected with the atmospheric opening 26 and the lower side of its piston rod sliding in a smaller cylindrical portion containing the channel 4 is acted upon by the train pipe pressure'existing in channel 4. The piston valve 20 serves for the control of the train pipe connections 5, '1 and 9 of the train pipe chamber F, of the standard pressure chamber E and of the valve chamber K, in such a manner that with the release position of the brakes shown these channels are open, as the piston 20 is elevated by the train pipe pressure acting on the lower side of the piston rod, while in the braking position they are shut off by the controlling piston 20 being loaded on its large upper face by the brake cylinder pressure with a force overcoming the force acting on the small lower piston rod face. A groove 11 near the piston 20 leaves the spaces above and below the piston in connection with the atmospheric connection 26 in the release position of the brakes.

The action of the device is as follows:

On charging the brakes the compressed air passes from the train pipe D to the controlling piston space 4, raises the piston 20 and fills through the passages 5, '7, 9 the chambers F, E together with C, and K together with B; it passes at the same time to the chamber F also through the restricted connection 2 and to K and B through the check valve 12.

With braking by reduction of pressure in the train pipe D air first flows from E and C back to the train pipe. As the train pipe chamber F is considerably smaller than the combined capacity of E and C, and the outlet openings 5 and '7 are of the same size, the pressure in F drops more rapidly than in E, so that the diaphragm L moves to the right, causes the spring plate 24 to press upon the piston rod 21 and makes the connection by the double valve 18 from the valve chamber K and the auxiliary reservoir B to the second brake cylinder chamber I and the brake cylinder A. As the auxiliary reservoir B is connected to the chamber K merely through a throttled passage, the pressure in the chamber K drops, by streaming of its air to the brake cylinder, more rapidly than in the auxiliary reservoir and in the train pipe. Therefore at the same time air passes from the auxiliary reservoir 13 and also directly from the train pipe D through the check valve 12 to K, I and A, so that the-reduction of pressure in the train pipe is accelerated within the predetermined limits.

./ It will be understood from the foregoing that upon beginning of the braking operation the air pressure in chamber K will be reduced more rapidly than in the main line 3 because the auxiliary air receptacle 3 is connected through narrow passages only with the chamber K and hence the air can flow slowly from the auxiliary receptacle B to the chamber K. It is for this reason being filled with air the main line during that chamber K is also through the valve 12 from the braking operation.

Upon obtaining the appropriate brakingpressure the downward moving controlling'piston 20 shuts off the openings 5, 7,9, in about /4 of a secondr Therewith only' then remains open, so as to lengthen the further pressure adjustments of the chamber F to the train pipe pressure, whereby the adjustment of a predetermined braking pressure is carried out in a precisely predetermined lengthened time being independent of the capacity of the brake cylinder due to the large passages on the latter allowing a more rapid pressure change in the brake cylinder than in chamber F. This means that even with cars equipped with very different brakes connected together in a long train the braking of all the cars throughout follows uniformly in exact dependence upon the adjusted train pipe pressure, so that any hard buffing of the cars upon one another, or a parting of the train, is avoided with great reliability. The auxiliary reservoir B remains connected with the brake cylinder A until the brake cylinder pres-.

sure presses back the diaphragm N (or M, according to the adjustment of the cock 16) to an extent such that the double valve 18 again closes. For example, if the train pipe-pressure is reduced by about one atmosphere, then with the dimension-ratio of the diaphragms L and N as 3:1, whichv is used in the example, a brake cylinder pressure of 3 atmospheres is given, on the occurrence of which the coupled diaphragms L, M, N come into equilibrium and allow the double valve 18 to close upon both seats. Any disturbances whatsoever of this equilibrium by air losses from the brake cylinder or at any other place effect then the corresponding supplementary air supply so that any adjusted braking pressure which may be desired remains maintained.

For unloaded cars in accordance with the object in view the larger diaphragm M comes into action and therewith the ratio of L:M equals 1,666z1. by one and a third of an atmosphere is made for a complete application, then the maximum braking pressure given for the loaded cars is 3, 6 atmospheres and for the unloaded cars is 2 atmospheres.

The regulating spring 22 arranged in the easing of the diaphragm L acts as follows: The regulating spring 22 although under its own constant tension can be acted upon by two different forces. In the case of loaded cars the diaphragm N may be subjected to the maximum permissible pressure, in this instance, of 3, 6 atmospheres and, in the case of unloaded cars, the diaphragm M which is accordingly larger than the diaphragm N may be subjected to the maximum permissible pressure for unloaded cars of two atmospheres. The regulating spring 22 comes into action by yielding when following an overcharge of the train pipe and accordingly of the standard pressure chamber E, C, the pressure in the train pipe chamber F is reduced to the prescribed value for the' full operation of the brakes or when, the train-pipe and the chambers E and C having been charged to the normal value, the pressure in the train pipe chamber F is reduced below the prescribed value for the full operation of the brakes, because in both cases the normal maximum pressure difference, being for instance 1, 2 atmospheres, between the pressures of chambers E and F is transgressed and therefore the diaphragm the throttled passage 2 If a reduction of the train pipe pressure L with the spring casing 23 is still pressed against the partition 0, when the maximum desired brake cylinder pressure, for instance 3, 6 atmospheres in chamber J is already reached. In this case the brake cylinder pressure acts for instance on the diaphragm N and, by means of the piston rod 21, on the stop plate 24 and the spring 22, so as to compress the latter and to lift the stop plate from the abutment fixed on the diaphragm L, due to the, predetermined small tension of the spring. Therefore the spring causes the seat of the double valve 18 between the auxiliary reservoir B, K and the brake cylinder chamber I to be closed, so as to avoid any overcharging of the brake cylinder. The spring does not come into action under normal circumstances. If, for instance, the train pipe pressure, after an overloading of the train pipe, is reduced by more than 1, 2 atmospheres, say to about 2 atmospheres, then the diaphragm L is displaced by the high pressure in the constant pressure chamber E up to the abutment an the projection of the intermediate wall 0, and at the same time the piston rod 21 and the double valve 18 are displaced, so that the chamber K and the auxiliary reservoir B are connected with the second brake cylinder chamber I and the brake cylinder. After the occurrence of the highest admissible pressure in the second brake cylinder chamber I then the piston rod 21 is again pressed back under the action of the brake cylinder pressure acting on the diaphragm N against the action of the spring 22, and the regulating spring 22, although the diaphragm L remains pressed against the intermediate wall 0, allows it with a sufiicient path by its ability to be compressed under the action of a predetermined force, so that the double valve 18 again closes and prevents too powerful braking, which would cause an overstrain of the brakes.

The regulating spring comes into action with similar effect whenever, after the train pipe had previously been charged to the normal maximum pressure, the pressure in the train pipe is reduced for braking below the admissible extent.

For the release of the brakes the pressure in the train pipe D is raised up to the pressure in the standard pressure chamber E and this pressure from the train pipe chamber F pushes back the diaphragm L, so that the brake cylinder pressure flexes the coupled diaphragms M, N and opens the piston-rod-channel 19 by removing the piston rod 21 from the double valve 18 so that the air in the brake cylinder escapes by the path 19, G, 25, 26. If only a partial raising of the pressin'e in the train pipe chamber F is made then equilibrium again occurs with a partial escape of the brake cylinder air, and the brake cylinder pressure is maintained at this intermediate value. With complete release of the brakes, after establishing atmospheric pressure in the second brake cylinder. chamber 1, then the controlling piston 20 goes up in consequence of the train pipe pressure acting upon its piston rod from below, and the entire system is again charged with compressed air ready for a fresh application of the brakes.

I claim:

1. A triple valve for direct acting automatic brakes, comprising in combination a diaphragm, a train pipe chamber connected to the train pipe on the one side of said diaphragm and standard pressure means acting upon the other side, a regulating spring and a spring plate arranged centrally on said diaphragm and being movable with it as a whole, an abutment on said diaphragm holding said spring under previous tension towards the train pipe chamber, charging and blow of! members for feeding and exhausting air on the brake cylinder and a movable member depending upon the brake cylinder pressure and controlling said charging and blow ofl members, said spring plate being opposed to said movable member, so as to yield under the action or the latter being loaded by the maximum desired brake cylinder pressure.

2. A triple valve for direct acting automatic brakes, comprising in combination a diaphragm, a train pipe chamber on the one side of said diaphragm and a standard pressure chamber acting upon the other side, a duct connecting said standard pressure chamber and said train pipe chamber, valve like means controlling said duct and adapted to connect the said standard pressure chamber to the train pipe, when tilled with air of high pressure, said train pipe chamber being connected to the train pipe through a throttled passage so as to lengthen the pressure adjustments of said train pipe chamber to the train pipe pressure and hereby determine the period of charging of the brake cylinder, a regulating spring and a spring plate arranged centrally on said diaphragm and being movable with it as a whole, an abutment on said piston like means holding said spring under previous tension towards the train pipe chamber, charging and blow off members for feeding and exhausting air on the brake cylinder and a movable member depending upon the brake cylinder pressure and controlling said charging and blow 011 members, said spring plate being opposed to said movable member, so as to yield under the action of the latter being loaded by the maximum desired brake cylinder pressure.

3. A triple valve for direct acting automatic brakes, comprising in combination a diaphragm, a train pipe chamber on the one side of said diaphragm and a standard pressure chamber acting upon the other side, a duct connecting said standard pressure chamber and said train pipe chamber, valve like means controlling said duct and adapted to connect the standard pressure chamber to the train pipe, when filled with air of high pressure, said train pipe chamber being connected to the train pipe through an alternately restricted and enlarged passage so as to lengthen the pressure adjustments of said chamber to the train pipe pressure and hereby determine the period of charging of the brake cylinder, a regulating spring and a spring plate arranged centrally on said diaphragm and being movable with it as a whole, and abutment on said piston like means holding said spring under previous tension towards the train pipe chamber, charging and blow of! members for feeding and exhausting air on the brake cylinder and a movable member depending upon the brake cylinder pressure and controlling said charging and blow off members, said spring plate being opposed to said movable member, so as to yield under the action of the latter being loaded by the maximum desired brake cylinder pressure.

4. A triple valve for direct acting automatic brakes, comprising in combination a diaphragm, a train pipe chamber connected to the train pipe on the one side of said diaphragm and standard pressure means acting upon the other side, a regulating spring and a spring plate arranged centrally on said diaphragm and being movable with it as a whole, an abutment on said diaadapted to connect selectively said diaphragm! to the brake cylinder, said spring plate being op-. posed to' said diaphragms, so as to yield under the action 01 the latter being loaded by the maximum desired brake cylinder pressure.

FLORENTIN KASANTZEFF. 

